Microencapsulation of walnut, peanut and pecan oils by spray drying

Understanding emulsifier influence on complex coacervation: Essential oils encapsulation perspective

The objective of this research was to explore the viability of pea protein as a substitute for gelatin in the complex coacervation process, with a specific focus on understanding the impact of incorporating an emulsifier into this process. The study involved the preparation of samples with varying polymer mixing ratios (1:1, 1:2, and 2:1) and emulsifier content. As core substances, black pepper and juniper essential oils were utilized, dissolved beforehand in grape seed oil or soybean oil, to minimize the loss of volatile compounds. In total, 24 distinct samples were created, subjected to freeze-drying to produce powder, and then assessed for their physicochemical properties. Results revealed the significant impact of emulsifier addition on microcapsule parameters. Powders lacking emulsifiers exhibited higher water solubility (57.10%-81.41%) compared to those with emulsifiers (24.64%-40.13%). Moreover, the emulsifier significantly decreased thermal stability (e.g., without emulsifier, Ton = 137.21°C; with emulsifier, Ton = 41.55°C) and adversely impacted encapsulation efficiency (highest efficiency achieved: 67%; with emulsifier: 21%).

Research progress of starch as microencapsulated wall material

Starch is non-toxic, low cost, and possesses good biocompatibility and biodegradability. As a natural polymer material, starch is an ideal choice for microcapsule wall materials. Starch-based microcapsules have a wide range of applications and application prospects in fields such as food, pharmaceuticals, cosmetics, and others. This paper firstly reviews the commonly used wall materials and preparation methods of starch-based microcapsules. Then the effect of starch wall materials on microcapsule properties is introduced in detail. It is expected to provide researchers with design inspiration and ideas for the development of starch-based microcapsules. Next the applications of starch-based microcapsules in various fields are presented. Finally, the future trends of starch-based microcapsules are discussed. Molecular simulation, green chemistry, and solutions to the main problems faced by resistant starch microcapsules may be the future research trends of starch-based microcapsules.

Recent Advances in the Microencapsulation of Essential Oils, Lipids, and Compound Lipids through Spray Drying: A Review

In recent decades, the microcapsules of lipids, compound lipids, and essential oils, have found numerous potential practical applications in food, textiles, agricultural products, as well as pharmaceuticals. This article discusses the encapsulation of fat-soluble vitamins, essential oils, polyunsaturated fatty acids, and structured lipids. Consequently, the compiled information establishes the criteria to better select encapsulating agents as well as combinations of encapsulating agents best suited to the types of active ingredient to be encapsulated. This review shows a trend towards applications in food and pharmacology as well as the increase in research related to microencapsulation by the spray drying of vitamins A and E, as well as fish oil, thanks to its contribution of omega 3 and omega 6. There is also an increase in articles in which spray drying is combined with other encapsulation techniques, or modifications to the conventional spray drying system.

Influence of the particle size of encapsulated chia oil on the oil release and bioaccessibility during in vitro gastrointestinal digestion

Among vegetable oils, chia oil has been gaining interest in recent years due to its high linolenic acid content (ALA, 18:3 ω3). The aim of this work was to study the influence of the particle size of encapsulated purified chia oil (PCO) on the encapsulation efficiency and PCO release during in vitro digestion. PCO micro- and nano-sized particles with sodium alginate (SA) as an encapsulating agent (ME-PCO-SA and NE-PCO-SA) were designed by micro and nano spray-drying, respectively, applying a central composite plus star point experimental design. NE-PCO-SA showed a smaller particle size and higher encapsulation efficiency of PCO than ME-PCO-SA (0.16 μm vs. 3.5 μm; 98.1% vs. 92.0%). Emulsions (NE-PCO and ME-PCO) and particles (NE-PCO-SA and ME-PCO-SA) were subjected to in vitro static gastrointestinal digestion. ME-PCO and NE-PCO showed sustained oil release throughout the three phases of digestion (oral, gastric and intestinal phases), whereas the PCO release from ME-PCO-SA and NE-PCO-SA occurred mainly in the intestinal phase, showing the suitability of sodium alginate as an intestine-site release polymer. Nano-sized particles showed a significantly higher PCO release after in vitro digestion (NE-PCO-SA, 78.4%) than micro-sized particles (ME-PCO-SA, 69.8%), and also higher bioaccessibility of individual free fatty acids, such as C18:3 ω-3 (NE-PCO-SA, 23.6%; ME-PCO-SA, 7.9%), due to their greater surface area. However, when ME-PCO-SA and NE-PCO-SA were incorporated into yogurt, the PCO release from both particle systems after the digestion of the matrix was similar (NE-PCO-SA, 58.8%; ME-PCO-SA-Y, 61.8%), possibly because the calcium ions contained in the yogurt induced partial ionic gelation of SA, impairing the PCO release. Sodium alginate spray-dried micro and nanoparticles showed great potential for vehiculation of omega-3 rich oils in the design of functional foods.

Effect of Wall Material and Inlet Drying Temperature on Microencapsulation and Oxidative Stability of Pomegranate Seed Oil Using Spray Drying

Pomegranate seed oil is a highly unsaturated fatty acid and liable to be oxidized; hence, oil was encapsulated to protect its bioactive materials and increase shelf life with the most common spray drying technique. Whey protein (WP) alone and in combination with Maltodextrin (MD) in the ratio 1:4 weight was utilized. Feed emulsion, droplet size, encapsulation efficiency (EE), moisture, bulk density, powder morphology, particle size, hygroscopicity, and solubility were also analyzed. The spray drying conditions were applied: inlet temperature 125 to 150°C and outlet 60 to 67°C, airflow rate 40-42 m³/mint, feed rate 5.2 g/m, and pump rate 40%. The shape of particles was spherical and round with dents on their surface. After encapsulation, the oxidative stability was monitored at 60°C for 15 days (8 h daily). The smaller droplet size of the emulsion was obtained at 35% total solid contents. WP alone showed better EE (90%) and oxidative stability than the combination of WP and MD as wall materials.

Influence of the Location of Ascorbic Acid in Walnut Oil Spray-Dried Microparticles with Outer Layer on the Physical Characteristics and Oxidative Stability

Purified walnut oil (PWO) microparticles with Capsul® (C, encapsulating agent), sodium alginate (SA) as outer layer and ascorbic acid (AA) as oxygen scavenger were obtained by spray drying using a three-fluid nozzle. AA was incorporated in the inner infeed (PWO-C(AA)/SA), in the outer infeed (PWO-C/SA(AA)) and in both infeed (PWO-C(AA)/SA(AA)). PWO-C(AA)/SA (4.56 h) and POW-C(AA)/SA(AA) (2.60 h) microparticles showed higher induction period than POW-C/SA(AA) (1.17 h), and lower formation of triacylglycerol dimers and polymers during storage (40 °C). Therefore, AA located in the inner infeed improved the oxidative stability of encapsulated PWO by removing the residual oxygen. AA in the SA outer layer did not improve the oxidative stability of encapsulated PWO since oxygen diffusion through the microparticles was limited and/or AA weakened the SA layer structure. The specific-location of AA (inner infeed) is a strategy to obtain stable spray-dried polyunsaturated oil-based microparticles for the design of foods enriched with omega-3 fatty acids.

Potential use of vegetable proteins to reduce Brazil nut oil oxidation in microparticle systems

Brazil nut oil is mostly composed of unsaturated fatty acids, some of which are associated with decreased incidence of cardiovascular diseases. Vegetable proteins have been increasingly used as wall material for partial replacement of carbohydrates and whey proteins. In order to create an oil preservation method, Brazil nut oil was encapsulated with three different types of vegetable protein concentrates and gum arabic (GA): rice (RPC + GA); pea (PPC + GA); and soy (SPC + GA) .For this purpose, vegetable protein concentrates were characterized, and after the drying process the physicochemical characteristics of the microparticles were evaluated. The most stable emulsion, after seven days of evaluation, was composed of RPC + GA. RPC + GA. This treatment was also more stable based on the shelf life assessments. We concluded that RCP microparticles were the best option for encapsulating Brazil nut oil in comparison with the other particles evaluated. In addition, the product obtained is potentially capable of being included in various processed foods.

Chemical composition and oxidative stability of eleven pecan cultivars produced in southern Brazil

Nuts are considered highly nutritious foods and a source of health-promoting compounds. Therefore, the aim of this study was to evaluate the chemical composition (proximate composition, fatty acids, volatile compounds, total phenolics, squalene, and β-sitosterol) of eleven pecan cultivars harvested in Rio Grande do Sul State (Brazil) and investigate their oxidative stability by the Rancimat method. 'Barton' is the main cultivar produced in Brazil and presented the highest protein, linoleic acid, and linolenic acid values and the lowest saturated fatty acid values, which provide health benefits. 'Mahan' showed the highest oxidation induction time, both in extracted oil and ground samples, low abundance of lipid oxidation compounds, low polyunsaturated fatty acids, high levels of oleic acid and β-sitosterol, which suggests potential for storage. 'Stuart' and 'Success' had the highest total dietary fiber values. Moreover, analysis showed that 'Chickasaw' and 'Success' had large quantities of compounds correlated to lipid oxidation, suggesting low stability for long-term storage. These results imply that the physicochemical characteristics and proximate composition of pecan nut cultivars from southern Brazil have variable parameters that may depend on their genetic variability.